function h = my_plotMainColorbar(Layout,Width,Climit)
	% handle_colorbar = my_plotMainColorbar(Layout,Width,Climit)
	% -------- custom function ------
	% description:
	%	set main colorbar for subplot figures
	% input:
	%	Layout: [rows,cols]
	%	Width:  width of colorbar
	%	Climit: caxis of subplot figures
	% output:
	%	handle_colorbar: handle of main colorbar
	% Author: Sid Chen
	% Date: 2022/1/8
	arguments
		Layout double
		Width double
		Climit double
	end

	% TN is total number of subplot figure
	TN = prod(Layout);
	subplot(Layout(1),Layout(2),TN-Width:TN);

	% plot colorbar
	h = colorbar('southoutside');
	axis off

	% set color range
	if isempty(Climit)
		Climit = caxis;
	end
	caxis(Climit);

end
